Replacing a bad breaker and lost device


#1

This was a bit of a surprise to me. I had a 15amp
Breaker that is a dedicated circuit for my heated tile floor. I needed to replace for no other reason that I wanted all my breakers to match in type, brand and looks. This floor heater had been detected and reporting and tagging perfectly.
I replaced the breaker with the same spec just another brand and now it has t reported a single time.
Something is viewed and calculating in the algorithms that sense is able to see the difference.
Just an FYI

I’ve deleted this device and we will see if it gets picked up again soon.

EDIT: sense named the device floor heater and was correct with off reporting. I’m not as sure about on reporting. Replacing the breaker also reset the thermostats setting an functions and I was unable to find how to set it up exactly as it was before.


#2

Did the new breaker go back into the same panel slot?


#3

Yes, it sure did @pswired. I was even careful to measure the depth the wire was inserted in to the old and orient it as close as possible. I made a painstaking job out of something that would usually not require any thought.
The one I replaced is square D. It was a home line breaker but I have a cutler Hammer panel that calls for BR Breakers. Eaton bought Cutler so that’s what it has.
It seems to have cured another problem I was having with an extremely (5ma) sensitive GFCI getting tripped on the floor. I suspect the fit was off just enough to cause an arc of sorts


#4

This sounds very strange. Unless something extraordinary was going on, replacing a breaker should have no bearing on device detection. The breaker behaves as a section of wire if everything is working properly.


#5

I had readnwhere someone had sense on water heater like I do and when they moved it the ended up having to reset.
It’s keeping me from moving to a dedicated breaker now.
I would say “signal loss” or differences are the reason. If there is more or less contact area between breakers it could change readings on a nearly undetectable level.


#6

If you move the breaker, the device will potentially end up on a different leg of service, or will have different subcomponents on different legs of service in the case of a 120/240 device, which could break the device model. But replacing a breaker without configuration changes should not carry this risk.


#7

I realize that but that’s only if there is a single pole between the doubles. If I put a new breaker under my water heater breaker and wire it the same with black on top red on bottom then they will be on same leg. The right and left side of panel doesn’t determine the leg. Every other single space on each side alternates legs. Otherwise a double 240 would pull 120 twice off same leg.


#8

I’ll eventually change it but if I lose any detections then I will do as suggested by another. He had a good thought. Twist cap water heater and sense together and then single tap the breaker with one wire for each leg. It would be within NEC that way.
I have a feeling that’s how this isn’t going to end based on taking a device and plugging it into another receptacle. That loses detection also


#9

A circuit breaker is basically a mechanized bimetallic strip. Without doubt different brands use different internal mechanisms, including probably the actual bimetallic strip itself that makes the breaker function. It’s possible (but don’t take my word for it, I’m neither an electrical engineer nor a Sense employee) that even the slight change in resistance in that strip from the old breaker to the new breaker has caused Sense to not recognize the connected load any longer.


#10

That’s exactly my thought, if strip in one is wider or thicke gauge than the other then I think there must be ad difference


#11

I don’t think this is likely. If there was enough resistance within the breaker to cause a substantial change in the power profile of the downstream load, there would be enough heat dissipation in the trip mechanism to trip the breaker.


#12

I stalled tho electric heat
Under the tile floor last January. Since then, th thermostat ( GFCI protected) would trip sometimes, a lot actually.
One problem is the extreme sensitivity.
At 5miiamp protection instead of the standard 15 amp protection I’ve racked my brain and talked many time with the manufacturer.
All these for the heating wire passed without fail.
The one thing I knew was not right was me using a home line breaker instead of a BR breaker. I could t see how it would be possible to cause a problem as the breaker was upstream of the thermostat. But since I’ve installed the correct breaker, there hasn’t been a single trip since.
It doesn’t make any sense to me and I’m absolutely not an expert on it anyway. But it seems to have cured the problem. That’s what pushed me to a somewhat loose coneecrion. The homeline van work with BR and vice versa but are not the “correct” wat to do it. I will surely be watching to verify this is a true fix.
Is there a better explanation? Please enlighten me.


#13

Hard to say. Here’s a thermal image of a breaker panel in use under varying loads on each circuit - you can see several different temperature variants on both the breaker as well as the wires depending on how many amps each breaker is passing.

A breaker does warm up under normal operation (not just before tripping) so that warming may be what’s varying the resistance value, especially on a high load item like resistive heating elements.

breakerinfrared


#14

Wow, @oshawapilot
Can I ask if that is your image and what you used. I’m trying to mark a completely unmapped panel and can see some usefulness here. The coolness factor is enough to impress me throroughly impress me. I want one!


#15

That’s thermal imaging. Everyone should have their panels scanned periodically looking for loose connections, failing breakers and overloaded circuits. Many insurance companies offer discounts for having this relatively inexpensive service done.


#16

Not my panel.

Thermal cameras can be had for a few hundred bucks nowadays. I even saw one in a pawn ship a few weeks back for $100.

I still can’t justify that sort of cost purely for a “toy” (for my needs, for others they are a valuable tool), however, but an alternative could be an infrared thermometer - these can be had for <$20, are pin-point accurate (may use a laser pointer to 100% narrow down what they’re reading), and although they don’t give you the nifty image, they will give you very accurate temperature data.


#17

Well, the only way I can think of to test this is to add in some resistance in series with a sense-identified device, then see if it’s still ID’d. Maybe I’ll gather together all of my extension cords one day and put them in series with my dehumidifier, then see what happens.


#18

Thank you for the information


#19

Also don’t forget that the older a breaker gets and the more on off cycles its done the more carbon buildup you get between the contacts so the older breaker would of had more resistance between the contacts than your new breaker.


#20

I replaced the breaker because I have a cutler box but I had installed a square d homeline breaker. It was supposed to be a BR style breaker. The electric floor GFCI kept tripping. It’s not an ordinary 15 amp GFCI, it ultra sensual 5 milliamperes. Way too sensitive.
Everything tests as it should and the manufacturer can’t figure out why. I was grasping at straws and thought, just maybe. Where it would trip many times a week. It has only tripped once since replacing with the correct brand and type. It might have tripped that time because of something I was doing at the time in the panel.
If it does t cure it I will be putting in a thermostat without GFCI built in and put in a regular GFCI breaker instead. I’m 100% sure that will fix it